IT 3100: Systems Design and Administration I
Relaying Email (Satellite Systems)
Due according to the class schedule.
It is important for outgoing email messages to be sent from most systems on a LAN through the centralized MTA. At this time in the semester, you should have several other systems on your LAN. (DNS, web, resources, file systems, etc.)
In this assignment, you will configure the MTA to relay email for these other systems, and to receive messages that were originally addressed for those systems.
You will also configure the systems to send their email messages through the MTA, and not to receive any email messages.
Throughout the semester these systems must continue to forward email through your MTA.
Configure LAN systems to relay all email through the MTA system
On each of the existing systems (except the MTA), install and
exim4 software to use your MTA as a smarthost.
On each of the existing systems, install the MUA
mailx via the
mailutils. Also install
These systems should be configured not to receive email.
Configure the MTA to receive incoming messages for the satellite systems
The server should accept email for users at any of the hosts in your domain. (e.g. firstname.lastname@example.org)
The DNS should be configured to direct any SMTP messages for any of the hosts in your domain to your MTA.
Configure the MTA to relay outgoing messages for the satellite systems
The email server should relay email for any user at any satellite system in your network. (e.g. Email from email@example.com should be relayed to its destination.)
User account creation
Create a new user account on the satellite systems. This should have the same username and password as the account created on the MTA system in the previous SMTP assignment.
Verify that your system is sending and receiving email messages correctly. You’ll want to consider the source and destination of the messages.
- Send from your MTA system
- Send from each satellite system in your LAN
- Send from an external system
- Send to your MTA system
- Send to each satellite system in your LAN
- Send to an external system
There are several locations to send from, and several locations to send to. This makes many possible combinations. To be sure your system is working correctly, check them all.
Use the log files to look for potential errors.
Submission File Format
The submission file is a UNIX text file, and must have this format, exactly!
The file must be named
mta: ip_address_of_MTA user: user_name_created_for_passoff pass: password_for_user host: name.of.mta.machine domain: name.of.domain hosts: ip_address_of_satellite_host1, ip_address_of_satellite_host2, ...
For example, my file might look like this:
mta: 126.96.36.199 user: bbonzai pass: $&^bbi13 host: mail.dsutux.us domain: dsutux.us hosts: 188.8.131.52, 184.108.40.206, 220.127.116.11, 18.104.22.168, 22.214.171.124, 126.96.36.199
Submission and Passoff
- Use the Submisions link at the
top of the page to submit your text file to the
Last Updated 08/07/2020